<template>
       <ul class="app-header-nav">
          <li class="home"><router-link to="/" >首页</router-link></li>
          <li v-for="item in list" :key="item.id" @mousemove="show(item)" @mouseleave="hide(item)">
            <router-link :to="`/category/${item.id}`" @click="hide(item)" >{{item.name}}</router-link>
            <div class="layer" :class={open:item.open}>
                <ul>
                    <li v-for="sub in item.children" :key="sub.name">
                        <router-link @click="hide(item)" :to="`/category/sub/${sub.id}`">
                          <img :src="sub.picture"  /><p>{{sub.name}}</p>
                        </router-link>
                    </li>
                </ul>
            </div>
          </li>
      </ul>
</template>

<script>
import { computed } from 'vue'
import {useStore} from 'vuex'
export default {
name:'AppHeaderNav',
 setup(){
    const store=useStore()
    const list =computed(()=>{
        return store.state.category.list
    })
    // 跳转的时候不会关闭二级类目，通过数据来控制
    // 1. vuex每个分类加上open数据
    // 2. vuex提供显示和隐藏函数，修改open数据
    // 3. 组件中使用vuex中的函数，使用事件来绑定，提供一个类名显示隐藏的类名
    const show = (item)=>{
          store.commit('category/show', item.id)
    }
     const hide = (item)=>{
          store.commit('category/hide', item.id)
    }
    return {list,show,hide}
  }
}
</script>

<style lang="less" scoped>
@import '~@/assets/styles/variables.less';
.app-header-nav {
  width: 820px;
  display: flex;
  justify-content: space-around;
  padding-left: 40px;
  position: relative;
  z-index: 999;
  > li {
    margin-right: 40px;
    width: 38px;
    text-align: center;
    > a {
      font-size: 16px;
      line-height: 32px;
      height: 32px;
      display: inline-block;
    }
    &:hover {
      > a {
        color: @xtxColor;
        border-bottom: 1px solid @xtxColor;
      }
      // 显示二级类目
      // > .layer {
      //   height: 132px;
      //   opacity: 1;
      // }
    }
  }
}
// 二级类目弹层
.layer {
  &.open {
    height: 132px;
    opacity: 1;
  }
  width: 1240px;
  background-color: #fff;
  position: absolute;
  left: -200px;
  top: 56px;
  height: 0;
  overflow: hidden;
  opacity: 0;
  box-shadow: 0 0 5px #ccc;
  transition: all .2s .1s;
  ul {
    display: flex;
    flex-wrap: wrap;
    padding: 0 70px;
    align-items: center;
    height: 132px;
    li {
      width: 110px;
      text-align: center;
      img {
        width: 60px;
        height: 60px;
      }
      p {
        padding-top: 10px;
      }
      &:hover {
        p {
          color: @xtxColor;
        }
      }
    }
  }
}
</style>